Magneto ignition device with inter



Aug. 14, 1945. OCHSENBEW 2,382,808

MAGNETO' IGNITION DEVICE WITH INTERRUPTER FOR INTERNAL-COMBUSTION ENGINES Filed June 12, 1943 AllllllA Y Y v I I V Y in h 10 J E If w l ar Ochsmbmb INVENTOR "6 ATTORNEY Patented Aug. 14, 1945 MAGNETO IGNITION DEVICE WITH INTER- RUPTER *FOR INTERNAL-COMBUSTION ENGINES Walter Ochsenbein, Bern, Switzerland, assignor to Hasler A. G.

Werke fiir Telephonie und Prazisionsmechanik, Bern, Switzerland Application June 12, 1943, Serial No. 490,704 In Switzerland February 2, 1942 6 Claims.

The present invention relates to a magneto ignition device having a multipole magneto and one or more interrupters for combustion engines, and where the number of the ignitions generated by the ignition device is twice as large as the number of the high tension impulses needed in the same space of time.

The invention consists in that for utilising of only each second half-wave of flux for forming the spark in the motor a rectifier is inserted into the primary circuit of the magneto.

Some embodiments of the invention are shown diagrammatically in the accompanying drawing.

l is the shaft of a cam wheel 3 controlling one interrupter arm 2' of a non represented multipolar magneto which may for instance be coupled directly to the controlling shaft of a four-stroke motor and the number ignition changes of which for each rotor revolution is twice as large as the number of sparks required for each revolution of the controlling shaft of the combustion engine. The interrupter arm 2 is arranged in a known manner being in contact with the cam wheel 3, which has a number of cams corresponding to the number of sparks to be generated at every revolution. In the illustrated embodiment only one cam has been shown. The interrupter lever 2 is connected on the one side with the inserted according to Fig. 1 into the circuit between the stationary contact of the interrupter and the framing. This rectifier prevents at each second half-wave oi flux which, as is supposed, shall not be used for ignition a current in the primary winding.

In the embodiment according to Fig. 2 the rectifier 6 is inserted between the framing and the primary winding 4 of the magneto. The eiiect is the same as in the embodiment of Fig. 1 and that of Fig. 3 where the rectifier 6 is inserted between the interrupter lever 2 and the primary winding.

In the embodiment according to Fig. 4 the rectifier 6 is inserted into a branch of current leading to the framing parallel to the interrupter. The arrangements of the rectifier according to Figs. 2 to 4 are also adapted for ignition devices where the interrupter as shown in Fig. 4 after having reached a sumcient speed of the motor respectively an ignition tension for generating a spark, is opened by a lever arm I and a rod 8 connected to a nOn represented self acting relieve device in order to spare the interrupter. In these embodiments contrary to that of Fig. 1 the rectifier is not switched off at a permanent liiting off of the interrupter arm.

When inserting a rectifier according to Fig. 1 each second opening of the interrupter interrupting the primary circuit at every change of flux is without effect because on account of the presence of the rectifier in the circuit of the interrupter no current is flowing at each second half-wave of flux in the primary circuit. Since then at the opening of the interrupter no short circuit current will be switched off, also the sudden rise of the magnet flux which is generatedin the high tension winding 9 and which generates the striking voltage, does not occur. Therefore a spark can arme only at eachsecond change of flux.

In the embodiment of Fig. 4 the rectifier as long as the interrupter arm is not permanently lifted oif from the stationary contact by means of the device 1, 8 works like in the embodiments of Figs. 2 and 3 in such a manner, that the primary current will flow only at each second change of In the embodiments of Figs. 2-4 a current will flow in the primary winding only at each second change of flux only then, when the interrupter by the device represented in Fig. 4 as an examu ple, is permanently lifted oil, that is when the change of flux produced by the magneto at every revolution is strong enough without interrupting the primary circuit to produce the high tension required for a spark generating. This has the consequence, that the creating or a magnetic field at each second change of flux will be prevented and that the number of sparks owing to the reduction of the number of flux-changes reduced to its half will be only half the number of flux-changes of the magneto.

In the connection of Fig. 4 a resistance I 0 is inserted into the circuit-branch of the rectifier which is dimensioned such that it limits the voltage oi the short-circuit choking coil to such an extent, that the subsequent flux-wave will not be damped.

It results from the above that the rectifier 6 may be provided in quite an ordinary magneto, as shown in Figs. 1 to 3, as well as also in a interrupter-lifting-ofi-device 'l, 8, as shown in Fig. 4.

It is of course or no account it the rectifier allows the passing of the positive or negative impulses of current.

01' importance is only this, that the high voltage impulses arise then. when the distributinglever of a suitable construction passes past a distributing electrode connected to a sparking P ug.

The described invention permits the working of any ordinary magneto used for igniting in combustion engines having when compared with the number of flux changes only half the number or an even or uneven number of cylinders and permits also the direct coupling between magneto and controlling shaft. Such controlling-shaftmagnetos having an even number of flux changes may be used with the aid of a rectifier inserted into the primary circuit or the magneto for igniting multicylinder motors having an uneven number of cylinders. Hitherto only either controllingshaft-magnetos with a particular arrangement oi the rotor or magnetos operated by means of a transm ssion gear and having an even number of flux changes or magnetos provided with particular cams which open the interrupters only at every second change of flux as described for instance in the Swiss Patent paper No. 128,064 could be used for this purpose.

In the shown embodiment only one cam wheel and one interrupter lever have been shown. It is however a matter of course that in certain cases two or more cam wheels on the same shaft and also two or more interrupter levers operated by the same.

What I claim is:

1. A hgh tension magneto ignition system for internal combustion engines comprising a multipolar magneto including a magnetic core having a primary and secondary winding thereon with the primary winding adapted to have an alternatthe intermittent breaking of said contact points.-

a distributor in the secondary circuit operated by the engine synchronously with the interrupter for successively firing the spark plugs of the engine, and a rectifier in said primary circuit for disabling the inductive eiiect in said secondary circuit during one-half of the alternating current cycle to reduce the number or spark plug firings to halt of that normally obtained in conventional magneto ignition systemsf 2 An apparatus as set forth in claim 1 wherein said primary circuit includes a grounded connection for one end oi the primary winding and another grounded connection leading i'rom the contact point remote from said winding with the rectifier interposed in said last-mentioned connection between said contact point and grounded connection.

3. An apparatus as set forth in claim 1 wherein said primary circuit includes a grounded connection for one end of the primary winding and another grounded connection leading from the contact point remote from said winding with the rectifier interposed between the other contact point and said first-mentioned ground connection.

4. An apparatus as set forth in claim 1 wherein said primary circuit includes a grounded connection ior one end oi the primary winding and another grounded connection leading irom the contact point remote irom said winding with the rectifier interposed in said first-mentioned grounded connection between the primary winding and ground.

5. An apparatus as set forth in claim 1 wherein said primary circuit includes a grounded connection for one end 01' the primary winding and another grounded connection leading from the contact point remote from said winding with the rectifier connected in parallel to the interrupter contact points.

6. An apparatus as set forth in claim 1 wherein said primary circuit includes a grounded connection for one end of the primary winding and another grounded connection leading from the contact point remote from said winding with the rectifier in series with a resistance connected in parallel to said interrupter contact points from a point between said primary winding and interrupter contact points to ground.

WALTER OCHSENBEIN. 

